Devices that are capable of absorbing infrared (IR) radiation, such as IR photodetectors, IR-to-visible up-conversion devices, and IR solar cells, have been attracting an increasing amount of attention due to their applicability to a wide range of fields, including night vision, image sensors, and renewable energy.
Certain nanoparticles show promise as IR-absorbing materials for use in IR-absorbing devices. For example, PbS nanoparticles generally exhibit excellent photosensitivity and bandgap tunability in at least a portion of the IR spectrum. However, due to the limitations of nanoparticle synthesis methods known in the art, PbS nanoparticles are mainly used in current devices to absorb electromagnetic radiation having a wavelength of less than about 1 μm. Accordingly, in order to capture portions of the IR spectrum having longer wavelengths, improved nanoparticle synthesis methods are needed.